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Abstract:

In embodiments of the present invention, a file access request sent by an
application to a hard disk is obtained, file information of the accessed
file is acquired according to the request, the file accessed by the
application is fragmented to obtain at least one file fragment, a
condition for copying the file fragment from the hard disk to the cache
is set, and the file fragment is copied to the cache when the copying
condition is met in a storage unit. Compared with a technical solution in
the prior art where the file is copied to the cache, utilization
efficiency of the cache is effectively improved.

Claims:

1. A method for implementing cache, comprising: obtaining a file access
request sent by an application to a hard disk, and acquiring information
about a file of an accessed file according to the request; fragmenting
the file accessed by the application according to the obtained
information about the file to obtain at least one file fragment; and
judging whether the obtained file fragment meets, within a preset time
segment, a condition for copying it from the hard disk to a cache; if
yes, copying the file fragment that meets the copying condition from the
hard disk to the cache.

2. The method for implementing cache according to claim 1, wherein, the
judging whether the obtained file fragment meets, within a preset time
segment, the condition for copying it from the hard disk to the cache
comprises: judging whether a frequency at which the obtained file
fragment is accessed within the preset time segment exceeds a first
preset threshold; or judging whether a frequency at which the obtained
file fragment is accessed within the preset time segment exceeds a first
preset threshold and whether a copying time preset according to a system
resource usage condition is met.

3. The method for implementing cache according to claim 2, further
comprising: when obtaining the file access request of the application,
judging whether a file fragment of a file requested for access is stored
in the cache; if yes, reading file fragment data requested for access
from the cache and returning the file fragment data to the application.

4. The method for implementing cache according to claim 2, wherein, the
judging whether the frequency at which the obtained file fragment is
accessed within the preset time segment exceeds the first preset
threshold comprises: judging a file type of the file accessed by the
application according to the file information, and when it is judged that
the obtained file type is a preset hotspot file type, judging whether a
frequency at which each file fragment of the obtained file is accessed
within the preset time segment exceeds the first preset threshold.

5. The method for implementing cache according to claim 1, further
comprising: when a file fragment stored in the cache is accessed,
updating an access frequency of the file fragment; and when a usage of a
cache capacity exceeds a second preset threshold, deleting a file
fragment whose access frequency does not exceed a third preset threshold
from the cache.

6. The method for implementing cache according to claim 1, wherein,
different first preset thresholds are set for different file types, and a
file fragment size is determined according to different file types.

7. The method for implementing cache according to claim 1, wherein, the
file information of the accessed file comprises: a file name, a file
path, and a file size.

8. A cache, wherein, the cache is placed above a file system and
comprises: a file information acquiring unit, configured to obtain a file
access request sent by an application to a hard disk, and acquire
information about a file of an accessed file according to the request; a
file fragmenting unit, configured to fragment the file accessed by the
application according to the obtained information about the file to
obtain at least one file fragment; and a storage processing unit,
configured to judge whether the obtained file fragment meets, within a
preset time segment, a condition for copying it from the hard disk to a
cache; if yes, copy the file fragment that meets the copying condition
from the hard disk to the cache.

9. The cache according to claim 8, wherein the storage processing unit
comprises: a judging sub-unit, configured to judge whether a frequency at
which the obtained file fragment is accessed within the preset time
segment exceeds a first preset threshold, or judge whether the frequency
at which the obtained file fragment is accessed within the preset time
segment exceeds the first preset threshold and whether a copying time
preset according to a system resource usage condition is met; and a
processing sub-unit, configured to copy the file fragment that meets the
copying condition from the hard disk to the cache when a judgment result
of the judging sub-unit is yes.

10. The cache according to claim 8, further comprising: an updating unit,
configured to, when a file fragment stored in the cache is accessed,
update an access frequency of the file fragment; and a releasing unit,
configured to, when a usage of a cache capacity exceeds a second preset
threshold, delete a file fragment whose access frequency does not exceed
a third preset threshold from the cache.

11. The cache according to claim 8, wherein the judging sub-unit is
specifically configured to: judge whether a file type of the file
accessed by the application is a hotspot file type; if yes, judge whether
the frequency at which the obtained file fragment is accessed within the
preset time segment exceeds the first preset threshold or judge whether
the frequency at which the obtained file fragment is accessed within the
preset time segment exceeds the first preset threshold and whether the
copying time preset according to the system resource usage condition is
met.

12. The cache according to claim 8, wherein, the cache is set with
multiple different interfaces and according to different features of the
interfaces, different copying policies may be selected, according to
different interfaces, for copying the file fragment to the cache.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of International Application No.
PCT/CN2011/070835, filed on Jan. 31, 2011, which claims priority to
Chinese Patent Application No. 201010116496.0, filed on Feb. 10, 2010,
both of which are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

[0002] The present invention relates to a storage technology field, and in
particular, to a method and an apparatus for implementing cache.

BACKGROUND OF THE INVENTION

[0003] A cache (Cache) is a special memory sub-system. Frequently used
data or a hotspot file is replicated in the cache to help reduce or
eliminate an impact of a speed difference between a CPU and a memory on
system performance. Taking that a solid state disk (Solid state disk,
SSD) is used as the cache as an example, in the prior art, when an
application accesses a particular file in the memory, the cache queries
whether this file is stored, and if the file is stored, directly returns
file data to the application. As data processing of the cache is always
faster than that of the preceding memory, the cache formed by the SSD
greatly increases a file access speed.

[0004] During implementation of the present invention, however, the
inventor finds that: a read request obtained by a cache in the prior art
includes only a start address and length of an accessed data block but
not a mapping relationship between the data block and a file; the data
block may correspond to several files, and not all of the several files
corresponding to the data block are frequently accessed data or hotspot
files; therefore, recognition accuracy of a hotspot file is reduced, and
utilization efficiency of the cache is thereby reduced.

SUMMARY OF THE INVENTION

[0005] Embodiments of the present invention provide a method and an
apparatus for implementing cache so as to effectively improve utilization
efficiency of a cache.

[0006] An embodiment of the present invention provides a method for
implementing cache, which includes:

[0007] obtaining a file access request sent by an application to a hard
disk, and acquiring file information of an accessed file according to the
request;

[0008] fragmenting the file accessed by the application according to the
obtained file information to obtain at least one file fragment; and

[0009] judging whether the obtained file fragment meets, within a preset
time segment, a condition for copying it from the hard disk to a cache;
if yes, copying the file fragment that meets the copying condition from
the hard disk to the cache.

[0010] An embodiment of the present invention further provides a cache,
which includes:

[0011] a file information acquiring unit, configured to obtain a file
access request sent by an application to a hard disk, and acquire file
information of an accessed file according to the request;

[0012] a file fragmenting unit, configured to fragment the file accessed
by the application according to the obtained file information to obtain
at least one file fragment; and

[0013] a storage processing unit, configured to judge whether the obtained
file fragment meets, within a preset time segment, a condition for
copying it from the hard disk to a cache; and if yes, copy the file
fragment that meets the copying condition from the hard disk to the
cache.

[0014] In the embodiments of the present invention, the file accessed by
the application is fragmented to obtain a file fragment, the condition
for copying the file fragment from the hard disk to the cache is set, and
the file fragment is copied to the cache when the copying condition is
met in a storage unit. Compared with a technical solution in the prior
art where the file is copied to the cache, the utilization efficiency of
the cache is effectively improved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To better illustrate the technical solutions in the embodiments of
the present invention or in the prior art, the accompanying drawings that
need to be used in the embodiments are briefly described. Apparently, the
accompanying drawings described below illustrate only some embodiments of
the present invention, and those skilled in the art may obtain other
accompanying drawings based on these accompanying drawings without
creative efforts.

[0016] FIG. 1 is a flowchart of a method for implementing cache according
to an embodiment of the present invention;

[0017]FIG. 2 is a flowchart of another method for implementing cache
according to an embodiment of the present invention;

[0018]FIG. 3 is a flowchart of another method for implementing cache
according to an embodiment of the present invention;

[0019]FIG. 4 is a block diagram of a structure of a cache according to an
embodiment of the present invention; and

[0020]FIG. 5 is a block diagram of a structure of another cache according
to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To make the preceding purpose, features, and advantages of the
present invention more explicit, the following describes the present
invention in further detail with reference to the accompanying drawings
and embodiments.

[0022] Referring to FIG. 1, an embodiment of the present invention
provides a method for implementing cache, which includes the following
steps:

[0023] Step 100: Obtain a file access request sent by an application to a
hard disk, and acquire information about a file of an accessed file
according to the request.

[0024] In the prior art, as the cache is located below a file system, the
read request received by the cache includes only a start address and
length of an accessed data block but not a mapping relationship between
the data block and a file. In this embodiment of the present invention, a
cache module is placed above the file system so that when the application
accesses a particular file or directory, the cache may receive the access
request of the application and acquire information about a file being
accessed by the application, including a file name, a file path, a file
size, and so on; in this way, the information about the file being
accessed by the application may be known, including the file name, the
file path, the file size, and so on.

[0025] Step 101: Fragment the file accessed by the application according
to the obtained information about the file to obtain at least one file
fragment.

[0026] For example, a size of file A is 100 MB. Assume that a file
fragment size is 10 MB. In this case, the file is first logically divided
into 10 fragments, where file fragment sizes corresponding to different
file types may be preset. For example, a media file fragment may be 70 MB
in size, and a small file such as a ringback tone file is not fragmented.

[0027] Step 102: Judge whether the obtained file fragment meets, within a
preset time segment, a condition for copying it from the hard disk to a
cache.

[0028] In this embodiment of the present invention, a hotspot file
fragment that is frequently accessed in a file is copied to the cache.
Determination and statistics collection of the hotspot file fragment have
a particular relationship with time segments. For example, an access
condition of video on demand in an on-duty time segment greatly differs
from that in an off-duty time segment. An access condition of a video
during a holiday also differs greatly from that in a common day.
Therefore, during collecting statistics about an access frequency of the
file fragment, a time segment for the statistics collection may be set
according to an actual condition, for example, the specific statistics
collection time, a statistics collection duration, and so on.

[0029] Step 103: If the judgment result is yes, copy the file fragment
that meets the copying condition from the hard disk to the cache.

[0030] Where, as a function of a cache is to serve as a match to adjust a
gap between devices with a large difference in transmission speed and
reduce an impact of a speed difference between a CPU and a memory on
system performance, the cache needs to use a hard disk whose read/write
performance is higher than read/write performance of a hard disk that
stores the file accessed by the application.

[0031] In the solution of the preceding embodiment, the file accessed by
the application is fragmented to obtain a file fragment, the condition
for copying the file fragment from the hard disk to the cache is set, and
the file fragment is copied to the cache when the copying condition is
met. Compared with a technical solution in the prior art where the file
is copied to the cache, utilization efficiency of the cache is
effectively improved.

[0032] Referring to FIG. 2, an embodiment of the present invention further
provides another method for implementing cache, which includes the
following steps:

[0033] Step 200: Obtain a file access request sent by an application to a
hard disk, and acquire information about a file of an accessed file
according to the request.

[0034] In the prior art, as the cache is located below a file system, the
read request received by the cache includes only a start address and
length of an accessed data block but not a mapping relationship between
the data block and a file. In this embodiment of the present invention, a
cache module is placed above the file system so that when the application
accesses a particular file or directory, the cache may receive the access
request of the application and acquire information about a file being
accessed by the application, including a file name, a file path, a file
size, and so on; in this way, the information about the file being
accessed by the application may be known, including the file name, the
file path, the file size, and so on.

[0035] Step 201: Fragment the file accessed by the application according
to the obtained information about the file to obtain at least one file
fragment.

[0036] Where, file fragment sizes corresponding to different file types
may be preset. For example, a media file fragment may be 70 MB in size,
and a small file such as a ringback tone file is not fragmented.

[0037] Step 202: Judge whether a frequency at which the obtained file
fragment is accessed within a preset time segment exceeds a first preset
threshold; if yes, go to step 203; if no, end the process

[0038] Whether the file fragment is a hotspot file fragment is determined
by judging whether the frequency at which the file fragment is accessed
exceeds the first preset threshold. In this solution, to improve judgment
efficiency, judgment on the hotspot file fragment may include:

[0039] judging whether a file type of the file accessed by the application
is a hotspot file type; if yes, judging whether the frequency at which
the obtained file fragment is accessed within the preset time segment
exceeds the first preset threshold.

[0040] Where, hotspot file types may be preset, and whether the file
accessed by the application is of a hotspot file type may be judged
through a file name extension during processing. When the file is of the
hotspot file type, a judgment is further made on whether the file
fragment is a hotspot file fragment, thereby improving processing
efficiency. For example, in a network television service, in addition to
a media file type, some auxiliary file types are also included, and the
cache may not process files belonging to these auxiliary file types.

[0041] Where, the determination and statistics collection of the hotspot
file fragment have a particular relationship with time segments. For
example, an access condition of video on demand in an on-duty time
segment greatly differs from that in an off-duty time segment. An access
condition of a video during a holiday also differs greatly from that in a
common day. Therefore, during collecting statistics about an access
frequency of the file fragment, a time segment for the statistics
collection may be set according to an actual condition, for example, the
specific statistics collection time, a statistics collection duration,
and so on.

[0042] In addition, the frequency at which the file fragment is accessed
within the preset time segment may also be obtained by setting times of
statistics collection within the preset time segment and comprehensive
analyzing an access frequency that is obtained from multiple times of
statistics collection with the preset time segment; where, statistics
obtained each time may undergo weighted average calculation to obtain the
frequency at which the file fragment is accessed within the statistics
collection time.

[0043] Where, a setting of the first preset threshold as the threshold of
the frequency at which the hotspot file fragment is accessed is related
to a file type, and different first preset thresholds corresponding to
access frequencies may be set for different file types.

[0044] Step 203: Judge whether a preset time for copying the file fragment
is met; if yes, go to step 204; if no, end the process.

[0045] Copying data in the hard disk to the cache needs to consume
resources such as CPU, memory, and hard disk bandwidth. To minimize an
impact of a new resource requirement introduced by copying on resources
required by the current access, in a case where it is determined that the
frequency at which the obtained file fragment is accessed within the
preset time segment exceeds the first preset threshold, a judgment is
made on whether the preset copying time is met, where, the preset copying
time may include a case where a CPU usage, a hard disk usage, or a memory
usage meets a preset condition.

[0046] Preferably, meeting the copying time may be the case where all
system resource usage parameters such as the CPU usage, the hard disk
usage, and the memory usage meet the preset conditions at the same time;
where, a user may set values of the system resource usage parameters when
the preset conditions are met, but the system may also provide an
experience value respectively, for example, 80% for the hard disk usage;

[0047] It should be noted that step 203 is a preferred step, and step 204
may be directly performed when the judgment result in step 202 is yes.

[0048] Step 204: Copy the file fragment that meets the condition from the
hard disk to the cache.

[0049] To further improve the utilization rate of the cache, preferably,
this method may further include the following steps:

[0050] Step 205: When the access request of the application is obtained,
judge whether a file fragment requested for access is stored in the
cache; if yes, read file fragment data from the cache and return the file
fragment data to the application.

[0051] Step 206: When the file fragment stored in the cache is accessed,
update the access frequency of the file fragment.

[0052] Step 207: When a usage of the cache capacity exceeds a second
preset threshold, delete a file fragment whose access frequency does not
exceed a third preset threshold from the cache.

[0053] In the technical solution of the preceding embodiment, the file
fragment accessed by the application is acquired, the judgment on the
hotspot file fragment is made by judging the access frequency of the file
fragment, and whether to copy the hotspot file fragment in a storage unit
to the cache is determined by combining usage conditions of computer
system resources. Compared with a technical solution in the prior art
where the entire file is copied to the cache, utilization efficiency of
the cache is effectively improved.

[0054] Referring to FIG. 3, by combining a specific application scenario,
an embodiment of the present invention further provides a method for
implementing cache, which includes the following steps:

[0055] Step 301: Receive a file access request delivered by an application
to a hard disk, and acquire information about a file of an accessed file
according to the request.

[0056] Step 302: Judge whether a file fragment of the file requested for
access is stored in the cache; if yes, go to step 309; if no, go to step
303.

[0057] Step 303: Judge whether a file type of the accessed file is a
hotspot file type; if yes, go to step 304; if no, go to step 308.

[0058] Where, hotspot file types may be preset. The hotspot file types may
be types of files whose frequencies of being accessed are high, or an
administrator may set the hotspot file types according to a specific
requirement. Whether a file fragment that needs to be accessed is of a
hotspot file type may be judged through a file name extension. For
example, in a network television service, in addition to a media file
type, some auxiliary file types are also included, and the cache may not
process files belonging to these auxiliary file types so as to improve
processing efficiency.

[0059] Step 304: Fragment the file to form file fragments, and perform
statistics collection on a frequency at which each file fragment of the
file is accessed.

[0060] Where, in this embodiment of the present invention, a cache module
is placed above a file system. Therefore, when the application accesses a
particular file or directory, the cache may know file information of a
file being accessed by the application, including a file name, a file
path, a file size, and so on.

[0061] Step 305: Judge whether the frequency at which each file fragment
is accessed exceeds a first preset threshold; if yes, go to step 306; if
no, go to step 308.

[0062] Where, a setting of the first preset threshold is related to a file
type, and different first preset thresholds corresponding to access
frequencies may be set for different file types.

[0063] Step 306: Judge whether a preset time for copying a file fragment
is met; if yes, go to step 307; if no, go to step 308.

[0064] Where, the preset copying time may include a case where a CPU
usage, a hard disk usage, a memory usage, or another system resource
usage parameter meets a preset condition; preferably, meeting the copying
time may be the case where all system resource usage parameters such as
the CPU usage, the hard disk usage, and the memory usage meet preset
conditions at the same time; where, a user may set values of the system
resource usage parameters when the preset conditions are met, but a
system may also provide an experience value respectively. For example, in
an IP video on demand service system, when 1200 concurrent streams of
access are supported, the system is already busy. Assume that the current
CPU usage already reaches 90%. In this case, if a hotspot file fragment
is copied from the hard disk to the cache, the CPU usage may probably
further increase, which may cause that the system fails to handle the
1200 concurrent streams of access during the copying process. Therefore,
to minimize an impact of a new resource requirement introduced by copying
on resources required by the current access, in a case where it is
determined that a frequency at which an obtained file fragment is
accessed within a preset time segment exceeds the first preset threshold,
preferably, the copying time is further considered.

[0065] Step 307: Copy a file fragment that meets the condition from the
hard disk to the cache.

[0066] Where, the cache may be formed by a solid state disk and be set
with multiple different interfaces, for example, a traditional interface
and a peripheral component interconnection-express (Peripheral Component
Interconnect-Express, PCIE) interface. According to different features of
the interfaces, different copying policies may be selected for copying
the file fragment to the cache. For example, in a large input/output
application, such as video processing, the PCIE interface may be selected
for copying a video file fragment to the cache.

[0067] Where, the cache includes a storage medium formed by a solid state
disk.

[0068] Step 308: Read data from the hard disk and return the data to the
application, and end the process.

[0069] Step 309: Read file fragment data requested for access from the
cache, return the file fragment data to the application, and update an
access frequency of the file fragment.

[0070] In this embodiment of the present invention, the file accessed by
the application is fragmented to obtain a file fragment, the condition
for copying the file fragment from the hard disk to the cache is set, and
the file fragment is copied to the cache when the copying condition is
met in a storage unit. Compared with a technical solution in the prior
art where the file is copied to the cache, utilization efficiency of the
cache is effectively improved.

[0071] Referring to FIG. 4, an embodiment of the present invention
provides a cache, which includes:

[0072] a file information acquiring unit 41, configured to obtain a file
access request sent by an application to a hard disk, and acquire
information about a file of an accessed file according to the request;

[0073] where, in this embodiment of the present invention, a cache module
is placed above a file system. Therefore, when the application accesses a
particular file or directory, the cache may receive the access request of
the application, and acquire information about a file being accessed by
the application, including a file name, a file path, a file size, and so
on;

[0074] a file fragmenting unit 42, configured to fragment the file
accessed by the application according to the obtained information about
the file to obtain at least one file fragment;

[0075] where, file fragment sizes corresponding to different file types
may be preset; and

[0076] a storage processing unit 43, configured to judge whether the
obtained file fragment meets, within a preset time segment, a condition
for copying it from the hard disk to a cache; if yes, copy the file
fragment that meets the copying condition from the hard disk to the
cache;

[0077] where, as a function of a cache is to serve as a match to adjust a
gap between devices with a large difference in transmission speed and
reduce an impact of a speed difference between a CPU and a memory on
system performance, the cache needs to use a hard disk whose read/write
performance is higher than read/write performance of a hard disk that
stores the file accessed by the application.

[0078] In the solution of the preceding embodiment, the cache fragments
the file accessed by the application to obtain a file fragment, and
judges whether the file fragment is a hotspot file fragment, thereby
effectively improving the utilization efficiency of the cache.

[0079] In the preceding embodiment, preferably, the storage processing
unit 43 may include:

[0080] a judging sub-unit 431, configured to judge whether a frequency at
which the obtained file fragment is accessed within the preset time
segment exceeds a first preset threshold, or judge whether the frequency
at which the obtained file fragment is accessed within the preset time
segment exceeds the first preset threshold and whether a copying time
preset according to a system resource usage condition is met;

[0081] where, a setting of the first preset threshold as a threshold of
the frequency at which the hotspot file fragment is accessed is related
to a file type, and different first preset thresholds corresponding to
access frequencies may be set for different file types;

[0082] where, to improve processing efficiency, the cache may process only
a file of a hotspot file type. Therefore, preferably, the judging
sub-unit 431 is specifically configured to: judge whether a file type of
the file accessed by the application is a hotspot file type, and if yes,
judge whether the frequency at which the obtained file fragment is
accessed within the preset time segment exceeds the first preset
threshold or judge whether the frequency at which the obtained file
fragment is accessed within the preset time segment exceeds the first
preset threshold and whether the copying time preset according to the
system resource usage condition is met;

[0083] where, hotspot file types may be preset. When a file is of a
hotspot file type, a judgment is further made on whether the file
fragment is a hotspot file fragment, thereby improving the processing
efficiency; and

[0084] a processing sub-unit 432, configured to copy a file fragment that
meets the copying condition from the hard disk to the cache when a
judgment result of the judging sub-unit is yes.

[0085] Referring to FIG. 5, an embodiment of the present invention further
provides a cache, which includes:

[0086] a file information acquiring unit 51, configured to obtain a file
access request sent by an application to a hard disk, and acquire
information about a file of an accessed file according to the request;

[0087] where, in this embodiment of the present invention, a cache module
is placed above a file system. Therefore, when the application accesses a
particular file or directory, the cache may receive the access request of
the application, and acquire information about a file being accessed by
the application, including a file name, a file path, a file size, and so
on;

[0088] a file fragmenting unit 52, configured to fragment the file
accessed by the application according to the obtained information about
the file to obtain at least one file fragment;

[0089] where, file fragment sizes corresponding to different file types
may be preset;

[0090] a storage processing unit 53, configured to judge whether the
obtained file fragment meets, within a preset time segment, a condition
for copying it from the hard disk to a cache; if yes, copy the file
fragment that meets the copying condition from the hard disk to the
cache; and

[0091] a data reading unit 54, configured to, when the access request of
the application is obtained, judge whether a file fragment of the file
requested for access is stored in the cache; if yes, read the file
fragment data requested for access from the cache and return the file
fragment data to the application.

[0092] In this embodiment, a data reading unit is added. When a file
access request is received, if the file fragment of the file is already
stored in the cache, the file fragment is directly read from the cache
and returned to the application. The cache reads faster than the hard
disk. Therefore, data read efficiency is effectively improved.

[0093] A read/write speed of a cache is higher than that of a common
memory. Therefore, the cost of a cache is high. To effectively use the
storage space in the cache, preferably, the cache further includes:

[0094] an updating unit 55, configured to, when the file fragment stored
in the cache is accessed, update an access frequency of the file
fragment; and

[0095] a releasing unit 56, configured to, when a usage of a cache
capacity exceeds a second preset threshold, delete a file fragment whose
access frequency does not exceed a third preset threshold from the cache.

[0096] In the solution of the preceding embodiment, the file fragment
accessed by the application is acquired, the judgment on the hotspot file
fragment is made by judging the access frequency of the file fragment,
and whether to copy the hotspot file fragment in a storage unit to the
cache is determined by combining usage conditions of computer system
resources. Compared with a technical solution in the prior art where the
entire file is copied to the cache, utilization efficiency of the cache
is effectively improved.

[0097] Through descriptions in the preceding embodiments, those skilled in
the art may clearly understand that the present invention may be
implemented through software by combining a necessary hardware platform,
or entirely through hardware. In most cases, however, the former is a
preferred implementation manner. The technical solutions in the present
invention may be essentially or the part that contributes to the prior
art may be embodied in the form of a software product. This computer
software product may be stored in a storage medium, such as ROM/RAM, a
disk tape, and a CD-ROM, and includes several instructions that are
configured for a computer device (which may be, for example, a personal
computer, a server, or a network device) to execute the methods described
in each of the embodiments of the present invention or some parts of the
embodiments.

[0098] The present invention is described in the preceding embodiments.
Several examples are used for illustration of the principles and
implementation manners of the present invention. The description of these
examples is used to help illustrate the methods and core ideas of the
present invention. Those skilled in the art can make modifications to the
specific implementation manners and application scopes according to the
ideas of the present invention. To sum up, content of this specification
shall not be construed as a limitation on the present invention.